The more or
less globose (apple shaped), typically furrowed capsules and the narrow
leaves with prorulose cells are distinctive family characters. The
roughenings are mostly eccentric over the lumen. Infrequently, most of the
laminal cells are smooth (a condition often associated with submergence in
boggy habitats) or, as in Plagiopus,
the leaves develop a striated cuticle which can appear papillose in section.